Tie rod assembly



Dec. 5, 1967 H. D. DRowN 3,356,396

TIE ROD ASSEMBLY Filed API'i] 17' 1967 United States Patent O 3,356,396 TIE ROD ASSEMBLY Herbert D. Drown, Saginaw, Mich., assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Filed Apr. 17, 1967, Ser. No. 631,342 3 Claims. (Cl. 287-58) ABSTRAC'I' OF THE DISCLOSURE A tie rod assembly is formed by placing transverse serrations near one end of `a rod having a sliding fit with the bore of an end housing. A clamping bolt extends through ears formed in transverse alignment on the housing. Circumferentially spaced serrations on the bolt operatively engage the serrations on the rod to accomplish endwise adjustment of the assembly by rotation of the bolt.

This invention relates to tie rod assemblies and more particularly to improved adjusting means therefor.

Tie rod assemblies conventonally employ so-called turn buckle adjustment means in which opposite hand internal threads are formed vat opposite ends of a sleeve member which threadably engages corresponding threads on associated rod elements. Adjustment of the overall length of the tie rod is accomplished by rotating the sleeve in the appropriate direction. When the desired length is attained, the sleeve is contracted into clamping engagement with the rod element by a suitable bolt means. While 'arrangements of this type perform adequately in initially establishing Iand maintaining the desired degree of the wheel toe-in in a vehicle Suspension and steering linkage arrangement, in some cases space limitations may be Critical to the extent that random rotational positioning of the turn buckle may cause interference between the locking bolt and adjacent portions of the vehicle. In addition, such constructions involve a multiplicity of threaded elements further complicated by the necessity of employing both right and left hand threads.

According to the present invention, a simplified and improved tie Arod assembly is provided which incorporates means for adjusting the vehicle wheel toe-in in ya manner whereby orientation of the adjustment locking bolt remains constant irrespective of manipulation involved in accomplishing initial or subsequent adjustments of toe-in.

According to a further feature, locking means embodying the present invention provide two stages of frictional retention for maintaining the tie rod linkage at the desired length.

The foregoing and other objects, advantages and features of the invention will become more fully apparent as reference is had to the accompanying specification and drawing Wherein:

FIGURE 1 is a fragmentary side elevational view, partly in section and with parts broken away, illustrating a portion of a tie vrod linkage incorporating the invention;

FIGURE 2 is a greatly enlarged sectional view looking in the direction of arrows 2-2 of FIGURE l; and

FIGURE 3 is Va fragmentary exploded view illustrating the component parts of the assembly and adjustment means therefor.

Referring now to the drawing and particularly FIG- URE l, there is shown one end of a tie rod assembly of the type employed in automotive steering linkage. While the primary purpose of steering linkage tie rod assemblies is to cause generally parallel tracking of the vehicle dirigible Wheels, the assemblies a-re also conventionally utilized to provide for adjustment in overall length in order to establsh and maintain a predetermined degree ice of wheel toe-in. In order to accomplish such adjustment V in accordance With the present invention, the tie rod assembly comprises a solid rod member 2 having an end portion 4 adapted for sliding interfitting engagement with a bore 6 formed in an end housing 8. End housing 8 includes a socket portion 10 formed at its outer extremity in which is disposed a ball stud member 12. It will be understood that stud member 12 is adapted for connection with associated portions of the steering assembly in the conventional manner.

According to the principal feature of the invention, tie rod end portion 4 is formed with a longitudinally extending recessed fiat portion 14 having uniformly spaced transverse serrations '15 coined therein which mesh with corresponding transverse serrations 16 formed around the midportion of a locking bolt 18. Locking bolt 18 is rotatably mounted in transversely aligned apertures 20 and 22 formed in offset ear portions 24 and 26 on housing 8. A longitudinally extending slot 28 is milled along the length of housing 8 midway between transverse extremities of ears 24 and 26 to a point somewhat beyond the latter so that the portion of housing 8 surrounding rod end 4 is caused to contract into frictional engagement therewith upon tightening the nut 30 on the threaded end 32 of bolt 18.

In operation, adjustment of the tie rod length is accomplished by loosening nut 30 sufficient to permit sliding movement of rod end 4 in bore 6. Bolt head 34 is then rotated either clockwise or counterclockwise causing the serrations 16 and 15, respectively, to function as a gear and rack imparting relative linear displacement of rod end 4 and housing 8. When the desi-red length has been achieved nut 30 is tightened while restraining the bolt head 34 against rotation.

Since, as previously mentioned, the housing 8 is slotted longitudinally, the aforementioned tightening of nut 30 contracts the housing 8 around rod end 4 and induces frictional locking action therebetween tending to maintain the selected position of adjustment. However, in addition to coventional locking engagement thereby achieved, the present invention provides an augmenting frictional lock in that tightening of nut 30 exerts tension loading on the nut and bolt tending to prevent rotation thereof, which in turn resists displacement of rod 2 because of mechanical engagement elfected by the respective serrated portions.

According to a further feature of the invention, means are also provided for preventing accidental complete withdrawal of rod end 4 from housing 8 when the nut and bolt are in a loosened condition. As seen best in FIGURES l and 3, the recessed longitudinal portion 14 terminates just short of the terminal end 36 of rod end 4 so that a lip portion 38 is formed by the latter which substantially intersects the space occupied by the midpo'rtion of bolt 18. Accordingly, complete extraction of rod end 4 from housing 8 requires total removal of bolt '18.

While but one embodiment of the invention has been shown and described, it will be apparent that other changes and rnodifications may be made therein. It is, therefore, to be understood that it is not intended to limit the invention to the embodiment shown, but only by the scope of the claims which follow.

I claim:

1. A tie rod assembly comprising, a tie rod having a transversely serrated recessed fiat portion formed near one end thereof, an end housing including a tubular portion surrounding said end of said tie rod, means forming a longitudinal slot in said tubular portion, integral bosses formed on said tubular portion at op'posite sides of said slot, said bosses having transversely aligned bores formed therein, an adjusting and retaining bolt extendng through said bosses, said bolt having a shouldered head at one end,

a transversely serrated midporton engaging the transverse serrations of said tie rod end, and a threaded opposite end extending outwardly from one of said bores for engagement With a nut and lock Washer, said rod and end housing being axially adjustable responsive to rotation of said bolt, and said adjustment being retained by tightenng said nut and lock washer.

2. The invention of claim 1 Wheren the inner diameter of said tubular portion is dimensioned so that tension loading of said bolt causes frictional clamping engagement between said inner diameter and said tie rod preventing relative axial movement therebetween and frietional engagement between said bolt'and said bosses preventing rotational movement of the former, thereby providing two separate but cooperating stages of locking retention.

3. The invention of claim 1 Wherein said recessed flat portion is spaced from the end of said rod thereby forming a radially projecting lip portion at the end of said rod preventing total retraction of said rod from said tubu- 5 lar portion.

References Cited UNITED STATES PATENTS lr CARL W. TOMLIN, Pl'im'ary Examiner.

W. L. SHEDD, Assistant Examiner. 

1. A TIE ROD ASSEMBLY COMPRISING, A TIE ROD HAVING A TRANSVERSELY SERRATED RECESSED FLAT PORTION FORMED NEAR ONE END THEREOF, AN END HOUSING INCLUDING A TUBULAR PORTION SURROUNDING SAID END OF SAID TIE ROD, MEANS FORMING A LONGITUDINAL SLOT IN SAID TUBULAR PORTION, INTEGRAL BOSSES FORMED ON SAID TUBULAR PORTION AT OPPOSITE SIDES OF SAID SLOT, SAID BOSSES HAVING TRANSVERSELY ALIGNED BORES FORMED THEREIN, AN ADJUSTING AND RETAINING BOLT EXTENDING THROUGH SAID BOSSES, SAID BOLT HAVING A SHOULDERED HEAD AT ONE END, A TRANSVERSELY SERRATED MIDPORTION ENGAGING THE TRANSVERSE SERRATIONS OF SAID TIE ROD END, AND A THREADED OPPOSITE END EXTENDING OUTWARDLY FROM ONE OF SAID BORES FOR ENGAGEMENT WITH A NUT AND LOCK WASHER, SAID ROD AND END HOUSING BEING AXIALLY ADJUSTABLE RESPONSIVE TO ROTATION OF SAID BOLT, AND SAID ADJUSTMENT BEING RETAINED BY TIGHTENING SAID NUT AND LOCK WASHER. 